Arrangement for synchronizing of telegraph apparatus



April 5, i938. R. HELL 2,113,429

ARRANGEMENT FOR SYNCHRONIZING 0F TELEGRAPH APPARATUS Filed Aug. 1].,1934 2 Sheets-Sheet 1 Q-Llvvszv-roii j w f April 5, 1938. R. HELL2,113,429

ARRANGEMENT FOR SYNCHRONIZING OF TELEGRAPH APPARATUS Filed Aug. 11, 19342 Sheets-Sheet 2 INVENTOR 7?u73o1.F HELL FY J/Q/Q dwm Patented Apr. 5,1938 TELEGRAPH APPARATUS Rudolt Hell, Berlin-Dahlem, Germany, assignorto Siemens & Halske, Aktiengesellschait, Siemensstadt, near Berlin,Germany, a corporation of Germany Application August 11, 1934, SerialNo. 739,383

\ 15 Claims.

This invention concerns improvements in and relating to synchronizingsystems for telegraph apparatus which transmits and records lettersignals as symbols analyzed into a succession of p constituent elementalareas or picture lines.

In the well-known telegraph apparatus which records received lettersignals analyzed into a succession of constituent elemental areas orpicture lines, for the purpose of allowing for faults due to "an inexactphase relationship between the transmitter and the receiver, a doublerecord of the letter in two parallel lines is eifected in such a mannerthat at least one of the letters is always recorded legibly. In sucharrangements no spe-' cial adjustment of the phase relationship isnecessary, but the recordings are not easy to read and sheet printing isnot possible.

In apparatus for picture transmission startstop-synchronizin'garrangements are well- 2 known, in which the transmitter transmitssynchronizing signals controlled by a tape on the picture drum of thetransmitter which are utilized to effect an adjustment of therelationship between transmitter and receiver if the transthe receiverdrum.

The present invention provides a synchronizing system for telegraphapparatus the receiver of which is arranged to record letter signalsanalyzed into picture lines by a magnet system and a rotatable recordingmember, in which the recording member is arranged to scan at least onelimiting surface of a normal recording base or area and means areprovided responsive to an en- 35 'croachment of the recorded letters onto a limiting surface, and operable upon such response to effect anadjustment of the phase relationship between the transmitter and thereceiver to restore synchronism therebetween. It can be so 40 arrangedthat the .degree of adjustment'of the phase relationship is eitherindependent of or -dependent upon the number of picture points which arerecorded on the limiting surface. The circuit for the adjustment of thephase relationship is 5 dependent upon one contact controlled by areceiving magnet system and a second contact which is arranged to beclosed by the rotatable recording member when the limiting surfaces arescanned. The adjustment of the phase relation- 50 ship can be controlledby a relay dependent for a mitted signals are recorded on a special tapeon In Germany August 11, 1933 (Cl.178- -69.5) T v 1 the picture-pointswhich are recorded on the limiting surface. The adjustment of phaserelationship can be effected by means of a short-circuiting device inthe circuit of the field winding of the driving motor of the receiver.It is also possible to adjust the .phase relationship by rotation of thestatorof thedriving motor or by a diilerential gear arranged between thedriving motor and the rotatable recording member. In

a further arrangement it is possible to provide 10 a coupling elementwith a controllable degree of slip between the driving motor'and therotatable recording member to efiect the phase adjustment.

The necessary adjustment of the phase relationship can also be efiectedby displacing the re- 15 cording member which produces the record in.picture lines, in the axial direction of the spindle thereof relativelyto the second strip. According to a feature of the invention theadjustment of the number of revolutions of the receiver mo- 0 tor iscontrplledby a displacement of the grid potential of an electricdischarge tube, in dependence upon thereceiv'ed letter signals and upona contact which is closed by the rotatable recording member; Therectification for generating the displacement potential is effected inone electrode system, the cathode of which is common with the cathode ofthe electrode system of which the grid potential is displaced foradjusting the number of revolutions of the receiver motor. Thiselectrode system is wellkn'own under the signification binode. Thebinodes are a combination of a grid-amplifierelectrode-system with atwo-electrode-rectifier of which one electrode is common with thecathode of the g'rid-amplifier-electrode-system. The v time constant ofthe grid circuit is, for instance, made equal to the period forrecording one picture line by switching in a condenser and resistancecombination of suitable values. The ad- 40 justment of the number ofrevolutions of the receiver motor is controlled by a relay which isswitched in the anode circuit of the discharge tube, or can be efiectedby means of a centrifugal governor or by other well-known methods.

The invention will be better understood from the following descriptionwhen considered in connection with the accompanying diagrammaticdrawings, Figs. 1-4.

Referring to the drawings, Fig-1 illustrates a tape l on which the wordBerlin is shown as recorded by a telegraph system to which the-inventionrelates. For the recording of the separate letters a base or surfacearea having a height of 2 cm. in the width of the strip is utilized.

recording arrangement is shown in Fig. 2, in

which a rotatable recording member 3 is provided mounted upon a spindlefor recording the analyzed picture lines, and is so arranged that a lineof the length of 4 (Fig. 1) can be scanned across the strip [which islonger than the length of the line 2 corresponding to the width of thebase for the transmitted letter signals. The re-' cording edge 4 (Fig.2) thus also scans the limiting surfaces of the recording surface 6forming the recording base for the letter signals. If by a phasedisplacement between the transmitter and the receiver the receivedsignals are record ed as picture lines encroaching on either of thelimiting surfaces 5, an adjustment of the phase relationship is effectedin the direction of leading or lagging, in accordance with which of thelimiting surfaces 5 is encroached upon by the letters.

As delineated above, a leading encroachment produces a decelerativecorrection and a lagging encroachment produces an accelerativecorrection. Were member 3 arranged always to lead, only means fordecelerative correction would be required, or. conversely only means foraccelerative correction, thus simplifying the arrangement.

When, as shown in Fig. 2, the receiving magnet system 1 is energized, itmoves its armature 8 in synchronism with the received signals andpresses a knife edgeon the armature against the recording strip l andapplies the strip against the rotating member 3, thereby effecting bymeans of an ink-ribbon not shown, the recording of the received lettersignals by the pressure exerted on the strip between the said knife edgeand the particular point of the helix 4 on the member 3,

member 3, at the moment when the helix 4 on the recording member 3 scansthe limiting surface 5 of the recording surface 6. The circuit 9 is onlyclosed when the contacts In and II are closed at the same time, that isthe moment when the recording of the letter signals occurs on a limitingsurface 5. In the circuit 9 an electro-magnet switch gear I3 isarranged, which effects the adjustment of the phase relationship by adifferential gear Hi, When the circuit 9 is closed.

Fig. 3 illustrates a modified arrangement in which the circuit l5 foradjustment of the phase is controlled by the two parallel connectedswitched contacts i6 and I1.

When the recording member 3 effects a record on the limiting surface 5of the recording base 6 the armature 8 of the recordingmagnet systemopens the contact I6, and the contact I? is at the same time interruptedby the cam l2. Thus the short-circuit for the resistance I9 in thecircuit of the driving motor I on the member 3 is also interrupted andan adjustment'of the phase relationship between the transmitter'andreceiver is effected.

Fig. 4 illustrates a further arrangement in ac-,

cordance with the invention, in which alternating current signals arereceived by an amplifier (not shown in the figure) and are transmittedover the .wires a, b to the receiving magnet EM, which records by meansof its armature bar S acting in conjunction with the rotating recordingmember A, the letter signals analyzed in picture lines, on thepaper-tape P through a carbon-backed tape. The recording member A is soarranged as to scan a picture line longer than the height of one letteras in the preceding arrangement and thus also scans the limitingsurfaces of the recording tape P. When a phase displacement between thetransmitter and the receiver occurs to an extent which effects therecording of the received signals on the limiting surface of the tape P,an adjustment of the phase relationship is effected.

During the period'of scanning the limiting surface a cam N on thespindle of the recording member A closes a contact T, and the receivedalternating current signals effect a displacement of the grid potentialof an electric discharge tube V and energize in the anode circuit arelay R which is arranged to efiect the necessary adjustment of thenumber of revolutions of the motor M. The discharge tube V is a binode,which contains, in addition to the normal triple electrode-system, afurther electrode E, which together with the normal indirectly heatedcathode constitutes a two-electrode rectifier system (diode-system) Thisrectifier system is arranged to effect the necessary rectification forgenerating the required displacement potential.

A constant grid potential is tapped from a battery D1 and supplied overa resistance R to the grid-circuit.- By suitable selection of the valueof the resistance R and of a condenser C bridging the resistance, thetime constant for the adjustment can be determined so that it is equalto the period for-recording one picture line, that is equal to theduration of one revolution of the recording member A.

The circuit of the two-electrode system for generating the displacementpotential includes a constant biasing potential derived from a batteryB2 through. a potentiometer resistance W, this biasingpotential beingopposed to the rectifying impulse-potential. By this means it ispossible to change the operating potential of the discharge tube foreffecting the adjustment. 'Alternating" potential impulses, for instancedisturbing potentials, the amplitude of which is smaller than thebiasing potential have no in fiuence on the adjustment.

In operation, with perfect synchronism there will be no current throughthe contact T and the relay R will be energized continuously to producecontinuous full speed operation of the motor M. With an out-of-phasecondition, contact T connects valve V in parallel with electromagnet EMduring the transmission of that portion of the signal which is inscribedupon the limiting surface of the recording base and this picture signalcurrent will flow from a, through C, E, and T, to b, charging thecondenser C to a potential varying in magnitude from cycle to cycleaccording to the variation in number of picture points or length ofpicture line inscribed upon the limiting surface. This polarization ofthe dotted grid will interrupt current through -relay R and restore thenormal speed of motor M. It will be seen that a greater degree ofrecording on the limiting surface will produce a greater magnitudev ofcharge on condenser C and a greater degree of control on relay R andmotor M, thus producing a greater correction to adjust the phasecondition.

The adjustment of the number of revolutions of the receiver station,which is controlled by the relay R in the anode circuit, can be effectedin different manners' For example, the armature of the relay R can beutilized to change the contact clearances of a centrifugal governor ofthe driving motor, so that with the setting of the adjustment circuitthe motor M is adjusted between two limits of the number of revolutionsthereof. This arrangement is especially advantageous, as no adjustmentof the anode current of the discharge tube is necessary.

What I claim is:

1. In a synchronizing system for telegraph apparatus, .the receiver ofwhich records letter signals analyzed in picture lines, the combinationwith an electrical responsive means, of a recording base having a normalrecording zone and a margin, a recording element for scanning therecording zone and the margin of the recording base, means controlled bythe recording element duriri'g the scanning period of the margin.

of the recording base, and means controlled by said last mentioned meansand the received letter signals for causing a phase regulationindependently of the recording of the letter signals.

2. In a synchronizing systemfor telegraph apparatus the receiver ofwhich records letter signals analyzed in picture lines, the combinationof an electrical responsive means, a recording member effective fromsaid means for recording characters on a strip, means for causing aphase regulation between the signals received and said recording member,an element operated in timed relation with said recording member, andmeans controlled jointly by the received letter signals operative onsaid electrical responsive means and by said element for controlling theoperation of said second mentioned means to cause a phase regulationindependently of the recording of characters. a

3. In a synchronizing system for telegraph apparatus, the receiver ofwhich records letter signals analyzed in picture lines, the combinationof a magnet system, a recording base provided with a normal recordingzone and limiting surfaces, a rotatable recording member arranged toscan the normal recording zone and also the limiting surfaces of therecording base, contact means arranged to be actuated by the rotatablerecording member during the scanning period of the limiting surfaces ofthe recording base, further contact means arranged to be actuated duringreceipt of a letter signal, means to vary the speed of said rotatablerecording member, and a speedcontrol circuit including said two contactmeans and said speed-varying means whereby the speed is varied inresponse to receipt of a letter signal during the scanning period of alimiting surface. 4. A system as claimed in claim 3 in which therecording member is arranged normally to rotate faster than thetransmitter and wherein said paratus the receiver of which recordsreceived letter signals analyzed in picture lines, the combination of atransmission line, a magnet system connected to said transmission line,a normal recording base provided with a normal recording zone and atleast one limiting surface, a rotatable recording member arranged toscan the normal recording zone and also at least one limiting surface ofsaid recording base, an armature member cooperating with said rotatablemember, a receiver driving motor, means for varying the speed of saidmotor, a contact controlled by said rotatable recording member, and adischarge tube connected to said transmission line and to said contactand to said means-for varying the speed ofthe motor, to cause receipt ofa signal from said line during closure of said contact to efiectvariation of speed of said motor. 7

6. A system according to claim 5, in which the discharge tube comprisestwo electrode systems having a cathode in common, one of said electrodesystems including rectifier means connected with said contact, and theother of said electrode systems being connected with said means forvarying the speed of the motor and including a grid connected with meansfor controlling the potential of said grid.

7. A system according to claim 5,-in which the dischargetube comprisestwo electrode systems having a cathode in common, one of said elec--trode systems being connected with said means for varying the speed ofthe motor and including a grid connected with means for controlling thepotential of said grid.

8'. A system according to claim 5, in which the discharge tube comprisestwo electrode systems having a cathode in common, one of said electrodesystems including rectifier means connected with said contact, and theother of said electrode systems being connected with said means forvarying the speed of the motor and including a grid in circuit with acondenser and a resistance of such values that the time constant of thegrid circuit will be equal to the period for recording one picture lineby said rotatable recording member.

9. A system according toclaim 5, in which the discharge tube comprisestwo electrode systems having a cathode in'common, one of said electrodesystems including rectifier means connected with said contact, and theother of said electrodesystems including an anode connected with a relayconstituting the means for varying the speed of the motor, such secondelectrode system also including a grid connected with means forcontrolling the potential of said grid.

10. In a synchronizing system for telegraph apparatus the receiver ofwhich records received said normal recording: base; first means respon-Ksive to a received letter signal, second means op-,

erated while,sald rotatable member is scanning I said limiting surface,and phase-adjusting meansoperatively connected with-said rotatablerecording member and also connected with said first means and saidsecond means-and responsive during an encroachment of the recordedletters on the limiting surface and operable upon such response toefiect an adjustment of the phase relationshipbetween the transmitterand the receiver.

11. In a facsimile recorder for recording received character signals insuccessive lines upon a record surface, a rotary member having angles ofrotation in which received character signals may be. recorded insuccessive lines in a normal recording zone of a record surfacealternating with intermediate angles of rotation in which receivedcharacter signals may be recorded upon' an edge zone of said recordsurface, phasing means for said rotary member, and means rendering saidphasing means operative to effect phasing in response to charactersignals received during said intermediate angles of rotation.

12. In a facsimile recorder for recording received character signals insuccessive lines upon a record surface, a rotary recording member havingpredetermined angles of rotation for recording received charactersignals in successive lines in a normal recording zone of a recordsurface alternating with other angles of rotation for recording receivedcharacter signals in an edge zone of said record surface, phasing meansfor said rotary recording member, and means associated with said phasingmeans and contin uously in phase with said recording member and furtherangle of rotation in which a received character signal may be recordedupon an edge zone of said record surface, phasing means for said rotarymember, and means rendering said phasing means operative to effectphasing in response to a character signal received in said furnormalrecording zone of a record surface and having another angle of rotationfor recording a received character signal in an edge zone of said recordsurface, phasing means for said rotary recording member, and meansassociated with said phasing means and continuously in phase with saidrecording member and operating to render said phasing means responsiveto a character signal received in said other angle of rotation of saidrotary recording member to effect phasing,

15. In a synchronizing system for telegraph apparatus, the receiver ofwhich records letter signals analyzed in picture lines upon a recordingsurface classified into a normal recording zone and an adjacentrecording zone, a rotatable recording member arranged to scan saidrecording zone and also said adjacent recording zone, electrical meansarranged to be controlledby said rotatable recording member during thescanning period of said adjacent recording zone, further electricalmeans arranged to be controlled during receipt of a letter signal, andspeed control means for said rotatable member including said electricalmeans and said further electrical means and adapted to vary the speed inresponse to a letter signal received during the scanning period of saidadjacent zone.

RUDOLF HELL.

